Diagnostic Ultrasound - Abdomen and Pelvis

Functional Ovarian Cyst
Diagnoses: Female Pelvis
– Placental human chorionic gonadotropin stimulates
CL progesterone production by granulosa-lutein cells
– Maintains uterine endometrium to receive embryo for
implantation
– CL progesterone production declines by end of 2nd
month of gestation
□ Placenta takes over production of progesterone
– CL present throughout pregnancy, though
significantly reduced in metabolic activity
□ Obliteration begins by 5th month of pregnancy and
is complete by term
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Majority of functional cysts are asymptomatic
○ Clinical presentation with pelvic pain due to
– Large size → capsular distension
– Rupture: 25% of women experience mittelschmerz or
ovulation pain
– Hemorrhage: Occurs into FC or CLC, acute bleed may
→ rupture/hemoperitoneum
– Torsion: Cyst enlarges ovary, may → torsion, infarction
• Other signs/symptoms
○ Palpable ovarian enlargement on clinical examination
○ FC may be discovered during infertility work-up
○ CLC incidentally noted on 1st trimester scan
Demographics
• Age
○ Follicular and CL cysts occur during reproductive years
○ Most fetal ovarian cysts are follicular
• Epidemiology
○ ~ 30% of menstruating women will have functional cyst
at some point
○ 25-60% of ovarian lesions in children are functional
ovarian cysts
Natural History & Prognosis
• Follicular cyst
○ May be associated with infertility: Oligo/anovulation
○ Estrogen levels are elevated: May interfere with
ovulation induction for assisted reproduction
○ When seen in female fetus, may be present with
intrauterine torsion
– Look for fluid-fluid level
– Most infants are asymptomatic at birth even if torsion
occurred
– Elective surgery may be indicated to fix contralateral
ovary
• Corpus luteum cyst
○ May enlarge initially with fertilization and pregnancy
– Peak size usually around 7 weeks
○ Should diminish in size with progression of pregnancy
○ Most no longer seen by sonography by early 2nd
trimester (16 weeks)
○ If cystic mass persists after pregnancy, consider ovarian
epithelial neoplasm
• Majority of functional ovarian cysts will resolve
spontaneously
• Torsion more common on right side and with cysts > 4 cm in
diameter
• Malignancy rate in unilocular simple cysts < 1%
Treatment
• Society of Radiologists in Ultrasound (SRU) consensus
statement on ovarian cyst management
○ Simple cyst
– Reproductive age women
□ No follow-up necessary ≤ 5 cm
□ > 5 and≤ 7 cm: Annual follow-up ultrasound
– Postmenopausal
□ > 1 and≤ 7 cm: Annual ultrasound
– Any age group with simple cyst > 7 cm
□ Refer for further imaging (MR) or surgical
evaluation
• Symptomatic treatment if painful
○ Oral contraceptive pill helpful if recurrent cysts
• If persistent may require laparoscopic surgery
○ Fenestration vs. cystectomy
○ Goal is preservation of normal ovarian tissue
DIAGNOSTIC CHECKLIST
Consider
• Functional cysts are common in reproductive age women
• Most do not require follow-up ultrasound
Image Interpretation Pearls
• CLC may have "ring of fire" appearance; located within
ovary
○ Beware of incorrectly diagnosing ectopic or heterotopic
pregnancy, which should be outside ovary
○ If uncertain whether intraovarian or adjacent to ovary,
use slide test
– Ectopic mass can often be displaced away from ovary
using gentle transvaginal probe pressure
• Even if CLC is persistent, may monitor through pregnancy if
no malignant features
○ Most likely a persistent functional cyst
SELECTED REFERENCES
1. Rosenkrantz AB et al: US of incidental adnexal cysts: adherence of
radiologists to the 2010 Society of Radiologists in Ultrasound guidelines.
Radiology. 271(1):262-71, 2014
2. Ghosh E et al: Recommendations for adnexal cysts: have the Society of
Radiologists in Ultrasound consensus conference guidelines affected
utilization of ultrasound? Ultrasound Q. 29(1):21-4, 2013
3. Valentin L et al: Risk of malignancy in unilocular cysts: a study of 1148
adnexal masses classified as unilocular cysts at transvaginal ultrasound and
review of the literature. Ultrasound Obstet Gynecol. 41(1):80-9, 2013
4. Faschingbauer F et al: Subjective assessment of ovarian masses using
pattern recognition: the impact of experience on diagnostic performance
and interobserver variability. Arch Gynecol Obstet. 285(6):1663-9, 2012
5. Levine D et al: Management of asymptomatic ovarian and other adnexal
cysts imaged at US: Society of Radiologists in Ultrasound Consensus
Conference Statement. Radiology. 256(3):943-54, 2010
6. Timmerman D et al: Simple ultrasound rules to distinguish between benign
and malignant adnexal masses before surgery: prospective validation by
IOTA group. BMJ. 341:c6839, 2010
802